South Korean high school students hold up their cards during a rally calling for South Korean President Park Geun-hye to step down in downtown Seoul, South Korea, Saturday, Nov. 5, 2016. Tens of thousands of South Koreans are expected to march in Seoul to demand President Park Geun-hye's resignation on Saturday, a day after she took blame for a "heartbreaking" scandal and rising suspicion that she allowed a mysterious confidante to manipulate power from the shadows. The signs read "Park Geun-hye should step down." (AP Photo/Ahn Young-joon)

South Korean high school students stage a rally calling for South Korean President Park Geun-hye to step down in downtown Seoul, South Korea, Saturday, Nov. 5, 2016. Tens of thousands of South Koreans are expected to march in Seoul to demand President Park Geun-hye’s resignation on Saturday, a day after she took blame for a “heartbreaking” scandal and rising suspicion that she allowed a mysterious confidante to manipulate power from the shadows. The letters read “Park Geun-hye should step down.” (AP Photo/Ahn Young-joon)

SEOUL, South Korea (AP) — Tens of thousands of South Koreans poured into the streets of downtown Seoul on Saturday demanding the resignation of President Park Geun-hye over a political scandal that has engulfed the nation.

The protest came a day after Park apologized on live television for the “heartbreaking” scandal amid suspicions that she allowed a mysterious confidante to manipulate power from the shadows, turmoil that is beginning to threaten her presidency.

Holding banners, candles and colorful signs that said “Park Geun-hye out” and “Treason by a secret government,” the demonstrators packed a large square in front of an old palace gate and nearby streets, singing and thunderously applauding speeches calling for the ouster of the increasingly unpopular president.

Police had anticipated that about 40,000 people would turn out for largest anti-government protest in the capital in nearly a year.

Police used dozens of buses and mobile walls mounted on trucks to create tight perimeters in streets around the square in front of the palace gate to close off paths to the presidential office and residence, known as the Blue House.

Thousands of officers dressed in yellow fluorescent jackets and full riot gear stood in front of and between the vehicles as they closely monitored the protesters.

Earlier in the week, prosecutors arrested Choi Soon-sil, the daughter of a late cult leader and a longtime friend of Park, and detained two former presidential aides over allegations that they pressured businesses into giving $70 million to two foundations Choi controlled.

South Korean protesters stage a rally calling for South Korean President Park Geun-hye to step down in downtown Seoul, South Korea, Saturday, Nov. 5, 2016. Tens of thousands of South Koreans are expected to march in Seoul to demand Park’s resignation on Saturday, a day after she took blame for a “heartbreaking” scandal and rising suspicion that she allowed a mysterious confidante to manipulate power from the shadows. The signs read “Park Geun-hye should step down.” (AP Photo/Ahn Young-joon)

There are also rising allegations that Choi, who has no government job, regularly received classified information and meddled with various state affairs, such as the appointment of ministers and decision of policies.

Smaller protests have taken place daily in past weeks in Seoul and other cities amid growing calls for Park to step down. While several politicians have individually called for the ouster of Park, opposition parties have yet to attempt a serious push for her resignation or impeachment in fear of negatively impacting next year’s presidential election.

Park has tried to stabilize the situation by firing eight aides and nominating three new top Cabinet officials, including the prime minister, but opposition parties have described her personnel reshuffles as a diversionary tactic.

One national poll released Friday had Park’s approval rating at 5 percent, the lowest for any president in South Korea since the country achieved democracy in the late 1980s following decades of military dictatorship.

In Friday’s televised apology, Park commented on the corruption allegations surrounding Choi and her former aides and vowed to accept a direct investigation into her actions, but avoided the more damning allegation that Choi perhaps had interfered with important government decisions on policy and personnel.

Opposition parties, sensing weakness, immediately threatened to push for her ouster if she doesn’t distance herself from domestic affairs and transfer the duties to a prime minister chosen by parliament. The parties have also called for a separate investigation into the scandal led by a special prosecutor.

Park has 15 months left in her term, and if she resigns before the end of it, South Korean laws require the country to hold an election to pick a new president within 60 days.

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